Sewing machine



' H. w. KRAG SEWING MACHINE Dec. 22, 1936.

Filed May 2'7, 1936 f/AS flrroeNEKs.

Patented Dec. 22, 1936 v [TED STATES PATENT OFFICE SEWING MACHINE Application May 2'7, 1936, Serial No. 82,000

7 Claims.

This invention relates to sewing machines, particularly shoe sole sewing machines of the type having a curved needle and a curved awl I that operate through a guide slot provided therefor in a work support or table. In such machines, the awl is thinner than the needle, whereby the space between the awl and the guide slot is greater than that required for working clearance. The use of thinner awls and needles for certain kinds of work and thread also increases the space between the needle and the front wall of the guide slot beyond that required for proper working clearance; and it also further increases the space between the awl and said front wall. A practical objection to such excessive clearances is that they permit the awl to spring out of position when piercing the work and thus cause the awl to break or to form a hole that is out of line with the needle and 20 thus cause the needle to break when it is sprung to enter said hole or is forced to pierce another hole in the work. Another objection is that the distance between the front edges of the needle and the awl and the front edge of the work 25 table varies with the thickness of the needle and awl used and thus renders such edge unsuitable for use as a gage for locating the line of stitching as close as possible to the upper of a shoe with needles and awls of different thicknesses.

30 The principal object of the invention is to overcome the disadvantages above described. Other objects are simplicity and cheapness of construction and compactness of design. The invention consists in providing the above type of 35 machine with a work table that may be adjusted to properly position the guide edge of the work table slot relative to needles and awls, of different thicknesses; it also consists in shaping said guide slot so: as to provide a proper working 40 clearance between the guide edge thereof and a needle of greater thickness than the awl; and it also consists in the construction, combinations and arrangements of parts hereinafter described and claimed. 45 In the accompanying drawing, wherein like symbols refer to like parts wherever they occur, Fig. 1 is a side view of a portion of a shoe sole sewing machine embodying my invention;

Fig. 2 is a plan view of the portion of the ma- 50 chine in the region of the needle, awl and work table; and

Fig. 3 is a fragmentary view of the underside of the work table and the portion of the machine adjacent thereto. 5 Referring to the accompanying drawing, my

invention is shown in connection with a shoe sole sewing machine comprising a stitcher head I, a curved needle 2 mounted in a holder 3 rotatably supported on a stud 4 secured to said head, a similarly curved awl 5 mounted in a holder 6 journaled on a feed slide 1 for rotation about the same axis as the rotary needle holder, and a work support or table 8 provided with an elongated guide slot 9 through which said needle and said awl operate. With this type of sewing 10 mechanism, the curved awl swings upwardly through the guide slot 9 in the work table 8 and pierces a hole in the work thereon and is then shifted laterally by means of the feed slide 1 into line withvthe curved needle 2 and is then retracted from the work, whereupon said needle swings downwardly through said hole into said slot to form the stitch. The construction of shoe sole sewing machine is well-known and it is considered unnecessary to illustrate it in detail.

In accordance with the present invention, the work support or table 8 is rigid with the free end of one arm of a lever 10 that is pivotally secured between its ends to the stitcher head I by a pivot screw H for swinging movement transversely of the needle and awl to properly locate the front edge of the elongated guide slot 9 relative to the convexly curved surface of the awl 5. The work table supporting lever I0 is swun about its pivot H by means of a stud I2 that is rotatably mounted in the stitcher head I at the free end of the other arm of said lever for rotation on an axis parallel to the work table pivot 'H and is provided with an eccentric pin l3 that engages a notch l4 in said end of said lever arm and is provided at its outer end with a screw driver slot I5. The stud I2 is provided with a collar 16; and a screw I1 is threaded into the stitcher head I and alongside of said collar with its head overlapping and bearing there- 40 against so as to retain said stud in said stitcher head and to hold it against rotation. As the needle 2 is usually made thicker than the awl 5, the portion of the guide slot 9 in the work table 8 has its front or guide edge oifset outwardly so as to provide the necessary working clearance between the needle and said guide edge without increasing the clearance between the awl and said edge.

By the arrangement described, the work table 8 may be readily adjusted transversely of the needle and awl by means of the stud I2 to obtain the proper working clearance between the guide edge of the work table slot 9 and the needle and awl and also to furnish proper supmachine for swinging movement transversely of port for the convexly curved side of the awl and thus force the awl to enter the work without springing forward and breaking or thus causing irregular sewing. The offsetting of the guide edge of the needle receiving portionof said guide slot enables the proper working clearance to be secured between said guide edge and the needle when the needle, in accordance with common practice, is made thicker than the awl. The work table adjustment also enables the line of stitching to be located as close as possible to the upper of a shoe with needles and awls of various sizes.

What I claim is:

1. In a sewing machine, a curved awl, a curved needle of greater thickness than said awl, and

a work support having a slot through which said awl and said needle operate, the portion of the edge of said slot opposite the convexly curved surface of said needle being ofiset with respect to the remaining portion of said edge to provide substantially the same working clearance between said needle and said edge as the working clearance between said awl and said edge,

2. In a sewing machine, a curved awl, a curved needle of greater thickness than said awl, a work support having a slot through which'said awl and. said needle operate, the portion of the edge of said slot opposite the convexly curved surface of said needle being offset with respect to the remaining portion of said edge to provide substantially the same working clearance between said needle and said edge as the work ing clearance between said awl, and said edge, and means for adjusting said work Support transversely of, said awl and said needle to obtain the desired working clearances between said edge of said slot and said awl and said needle.

3. In a sewing machine, a curved needle, a curved'awl, a member pivotally mounted on said said needle and said awl and provided with a work supporting portion having a slot therein through which said needle-and said awl operate,

,and means on said machine cooperating with said member for swinging the latter.

4, In a sewing machine, a curved needle, a curved awl, a member pivotally mounted on said said needle and said awl and provided on one armvvith a work supporting portion having an elongated slot therein through which said needle and said'awl operate, and means on said machine cooperating. with the other arm of said member for swinging the same on its pivot.

6; ma sewing machine, a curved needle, a curved awl, a lever pivotally mounted on said machine for swinging movement transversely of said needle and said awl and provided on one 'arm with a work supporting portio-n'having an elongated slot therein through which saidneedle and said awl operate, and means on said ma-. chine cooperating with the other arm of 'said' member for swinging the same on its pivot, said means comprising a stud rotatably mounted on said machine and provided with an eccentric pin adapted to engage an opening provided therefor in said other arm of said lever.

'7.'In a sewing machine, a curved needle, a curved awl, a lever pivotally mounted on said machine for swinging movement transversely of said needle and said awl and, provided on one arm with a work supporting portion having an elongated slot therein through which said needle and said awl operate, means onsaid machine cooperating with the other armof said member for swinging'the same on its pivot, said means comprising a stud rotatably mounted on said machine and'pro-vided with an eccentric pin adapted to engage an opening provided therefor in said other arm of said lever, and means for locking said pin in the desired position of its rotary adjustment.

HARRY W. KRAG. 

